This invention involves conducting an analysis of input ECG and related personal data for the purpose of detecting and giving certain information about sizing and location of old myocardial infarcts (MI). In particular, the invention focuses attention on the general architecture and organization of certain algorithms which play roles in the detection, sizing and locating tasks. Featured among other things as unique in the algorithms architecture of this invention are analyses based upon selected ratios of Q, R and S voltage amplitude values which are associated with ECG data received from certain ECG leads. Two different ECG lead protocols are described herein including the usual, standard 12-lead protocol, and a known, but less widely employed 15-lead protocol.
In the setting of an interpretation and analysis system employing the algorithms of this invention, input ECG, and certain related personal data, are conventionally collected and fed into the system. This input data can generally be described as follows in relation to one preferred embodiment and method of practicing the invention, ECG data relating to a particular subject is derived from a conventional 12-lead ECG intake protocol, with data particularly focused upon which comes from leads I, II, V1, V2, V3, V4, V5 and V6.
In a modified form and implementation of the invention, data from a larger, 15-lead input protocol is used, with such data including information from each of the eight specific leads just mentioned above, and in addition, from leads V8R, V 4R and V8.
From each lead, and regardless of the specific different ways in which different pieces of conventional EGG-collection equipment may perform, what is fed into the system is lead data from these eight leads which, in the case of each lead, is based upon500-Hz sampling, 5-microvolts per least significant bit, 16-bit information, with simultaneous (from the different leads) samples spanning a duration preferably of about 10-seconds.
As will become apparent from Data Tables that form parts of the present invention disclosure, the unique algorithmic structure of the present invention examines different R/Q and R/S voltage-amplitude ratios that are associated variously with EGG data derived from leads I (ratio R/Q), AVL (ratio R/Q), AVF (ratio R/Q), V1(ratio R/S). V2(ratio R/S), V4 (ratios R/Q, R/S), V5 (ratios R/Q, R/S), V6 (ratios R/Q, R/S), V4R (ratio R/S), V8 (ratio R/Q).
In addition to EGG lead information from the leads, and of the category, mentioned above, also provided as input data for implementation of the invention is certain subject- or patient-specific data, including, for example, age, gender and race.
This “block” of data is fed into the system wherein the very first step that is performed involves the detection of so-called confounders and excluders. Confounders, a term known in the art which embraces so-called conduction abnormalities and ventricular hypertrophies, include certain conditions, such as right bundle branch block (RBBB), left anterior fascicular block (LAFB) and left and right ventricular hypertrophy (LVH and RVH). Excluders include conditions such as the presence of a pacemaker, left bundle branch block (LBBB), Wolff-Parkinson-White syndrome, and others.
The presence of confounders and/or excluders fundamentally determines how and to some extent whether data interpretation and analysis proceeds, and the algorithms proposed by the present invention are designed to be capable of dealing with certain patterns of such first-level detected conditions present in the ECG input data.
Following determination of the presence and/or absence of confounders and/or excluders, and assuming that interpretation and analysis is determined to be doable by the system which employs the algorithms of the present invention, the ECG (and mid accompanying other personal data is subjected to measurements which look at various qualities of the ECG waveforms per se, and also including a look, where appropriate, and in accordance with a feature of the present algorithms, at certain vector ECG information. Based upon these selected measurements, analysis proceeds to determine, first of all, whether or not an old MI is present, and, following that, and if such a condition is detected, to perform an analysis regarding size and location.